Airplane Flying

An airplane is flying in a horizontal circle at a speed of 480 km/h (Fig. 6-42). If its wings are tilted at angle θ = 40° to the horizontal, what is the radius of the circle in which the plane is flying? Assume that the required force is provided entirely by an “aerodynamic lift” that is perpendicular to the wing surface.

Interesting; I didn't think there was enough information but it did work out.
I think you have mixed up the angle. In the y direction, Fn*cos(theta) - mg = 0.
I converted to meters and seconds - much easier! Got a little over 2 km for the radius.